Scuba diving is a mode of underwater diving in which the scuba diver uses a self-contained underwater breathing apparatus (scuba) which is completely independent of surface supply, to breathe underwater.
Scuba divers are trained in the procedures and skills appropriate to their level of certification by instructors affiliated to the diver certification organisations which issue these certifications. These include standard operating procedures for using the equipment and dealing with the general hazards of the underwater environment.Continue
By the mid twentieth century, two basic systems for scuba (self-contained underwater breathing apparatus) had emerged: open-circuit scuba where the diver's exhaled breath is vented directly into the water, and closed-circuit scuba where the carbon dioxide is removed from the diver's exhaled breath which has oxygen added and is recirculated.Continue
The first commercially successful scuba sets were the Aqualung twin hose open-circuit units developed by Emile Gagnan and Jacques-Yves Cousteau in 1943, in which compressed air carried in back mounted cylinders is inhaled through a demand regulator and then exhaled into the water adjacent to the tank.Continue